There are lots of good, bleeding-heart reasons to value diversity, to see it as a noble end in and of itself. But there are some very practical reasons to seek it out, too, as a new article in Perspective on Psychological Science points out.

The evidence on group diversity has been mixed overall, the researchers point out. They write: “More than half a century of research evidence has produced few straightforward or consistent characterizations of diversity’s influence on group process and performance, with some studies revealing beneficial effects and others documenting downsides.” Among the downsides is the fact that it’s harder to achieve group cohesion in heterogeneous groups than in homogeneous ones — humans have a tendency toward “homophily,” or being attracted to those who are like us.